OK, I went to Bogenimageing today and the guy there showed me a little trick. I have uploaded another video with this trick.

I think it makes the whole thing a whole lot easier. I put a 45x no name wide angle lens on the camera. But when I watched the video I saw, that I should have zoomed in a lillte bit, so that these ugly black corners wheren't there.

I think with holding the thumb just a little against the plastic, it makes look the video much smoother. With a little more practice I will probably turn out real good.